The present invention relates to the art of coating edible cores, and, in particular, to a method and apparatus for continuous pan coating edible cores.
The practice of applying a coating to edible particulate matter one cores by pan of coating generally includes placing the cores in a rotating drum which continuously agitates them while a solution of the coating material is applied, usually by spraying the material over the cores in the rotating drum during agitation. It is customary to coat edible cores such as nuts, chewing gum, candies, fruits, lozenges, dragees, and medicinal tablets with one or more layers of candy or sugar coating by conventional procedures using a drum or a rotatable vessel and warm air or other drying gas to evaporate and/or harden each layer in preparation for application of subsequent layers.
For example, U.S. Pat. No. 4,334,493 to Okawara shows a rotary drum type apparatus for applying a coating to tablets which includes a rotary drum supported by a frame for receiving a body of tablets to be coated by spraying with a solvent. The drum which can be inclined through about 10-20.degree. in such a manner that its front surface is turned upwardly, includes a device which supplies a coating material into the interior of the drum and an inlet tube and an outlet tube to provide a supply of drying gas such as air to the interior. The support frame cooperates with an outer periphery of the drum to define an air suction duct disposed on the front side of the support frame and an air exhaust duct disposed on the rear side of the support frame so that a smooth flow of hot blast through the drum can be obtained.
Similarly, in U.S. Pat. No. 4,245,580 to Okawara, a device for coating granular solids is disclosed which has a double-cone rotary drum perforated so as to permit flow of air or gas into and out of the rotary drum, and which is tiltable about the axis at right angles to the axis of rotation of the rotary drum so that in the case of the discharge of product solids, the opening of the rotary drum may be directed downwardly. Axial annular insulating covers are providing which insure the effective thermal insulation of the rotary drum when the hot air or gas is blown thereinto. However, each of the Okawara disclosures discussed above relate to coating drums for batch operation since each body of cores to be coated must be fed into and discharged from a single opening. Similar operation and apparatus are shown in U.S. Pat. No. 3,448,718; U.S. Pat. No. 3,063,843; and U.S. Pat. No. 2,726,959.
U.S. Pat. No. 3,911,860 to Nohynek discloses a coating drum for continuous coating of dragees with a coating material and for subsequent application and glossing of a protective skin over the coating by use of a co-axially connected after-treatment drum. In particular, both drums are fixed in a sealing connection to each other and may be driven at different speeds by means of a variable speed transmission rotationally interconnected. The dragee drum shown by Nohynek is a double frustum, while the after-treatment drum is cylindrical. Both drums are equipped with conveying baffles in order to push the product through from the entrance to the exit. On the inner wall of the rear frustum of the dragee drum are located conveying baffles 5 arranged in relation to the direction of rotation so that only a few dragees at a time are discharged through rear discharge opening 6. The discharge opening 6 leads to an inner drum 7 of approximately the same diameter through which the coated particles flow by means of conveying baffles 11 to radial transfer opening 17 into intermediate drum 10 on which there are also located helical screw type conveying baffles 5 and 13. The particles pass from intermediate drum 10 into the outer drum space 20 from which they emerge through discharge openings 21.
In each of these disclosures, as well as general practice in the art, there is lacking a method and apparatus for continuous pan coating of edible cores in which there is a high degree of control of the coating process.
Accordingly, it is an object of the present invention to overcome problems normally associated with the continuous highly controlled pan coating of edible particulate matter or cores.
It is another object of the present invention to provide an apparatus for continuous pan coating of edible cores with several layers of coating material.
It is a further object of the present invention to provide an apparatus whereby edible cores can be provided with a chocolate candy coating, as well as successive protective outer coatings over the chocolate coating.